Hong Kong authorities reported the city’s first Zika virus infection Thursday, which they described as an imported case of the disease blamed for birth defects.

The Zika-infected patient was said to be a 38-year-old female who had travelled to a Caribbean island, before complaining of pain in the joints and red eyes.

“Initial investigations show that the patient had travelled to the island of St. Barthelemy in the Caribbean Sea from August 6th to the 20th...she remembered that she was bitten by a mosquito,” Leung Ting-hung, head of the Centre for Health Protection, told reporters late Thursday.

The woman underwent a blood and urine test at an outpatient clinic at a private hospital on August 23, Leung said, describing her as a “foreigner” who lived in the rural district of Tseung Kwan O and worked in the financial district of Central.

Test results revealed she had Zika virus Thursday.

Leung said she is now being treated under quarantine in hospital and is in a stable condition.

“We will carry out relevant preventive and control measures to prevent further spread of the disease, as this is essentially a mosquito-borne disease, so the most important thing is to control the mosquito population in Hong Kong,” Leung said.

Until now, global health authorities have been primarily concerned with the danger Zika poses to pregnant women and their foetuses.

Zika causes only mild symptoms for most people. But in pregnant women, it can cause microcephaly, a deformation in which babies are born with abnormally small brains and heads.

The virus has also been linked to a disorder known as Guillain-Barre syndrome, which can lead to nervous system problems such as weakness and paralysis.

However, new research earlier this month using lab mice showed for the first time that Zika may damage adult brain cells involved in learning and memory.

The outbreak of the virus began in Brazil in early 2015 and has spread to neighbouring countries.

In southern United States, the state of Florida has reported a total of 524 Zika cases, most of them brought in by people who were infected while travelling to Latin America.

Thirty-six cases were locally transmitted, according to the state department of health.

Hong Kong is particularly alert to the spread of viruses after an outbreak of Severe Acute Respiratory Syndrome (SARS) swept through the city in 2003, killing 299 people and infecting around 1,800.

Bird flu scares in the past two years have seen mass culls of up 20,000 birds in Hong Kong.